3.2.4 - Computer Output

The computer output below shows the result of a linear regression analysis for predicting the concentration of zinc, in parts per million (ppm), from the concentration of lead, in ppm, found in fish from a certain river. Which of the following statements is a correct interpretation of the value 19.0 in the output?

• On average there is a predicted increase of 19.0 ppm in concentration of lead for every increase of 1 ppm in concentration of zinc found in the fish.

• On average there is a predicted increase of 19.0 ppm in concentration of zinc for every increase of 1 ppm in concentration of lead found in the fish.

• The predicted concentration of zinc is 19.0 ppm in fish with no concentration of lead.

• The predicted concentration of lead is 19.0 ppm in fish with no concentration of zinc.

• Approximately 19% of the variability in the zinc concentration is predicted by its linear relationship with lead concentration.

Tags

CCSS.HSS.ID.C.7

Given the following Minitab output, which of the following is false?

• 80% of the variability in y is explained by the linear relationship with x.

• Since r=0.898, the linear relationship between x and y is strong, positive, and linear.

• As x increases by one unit, y decreases, on average, by 1.6914 units.

• The intercept of the least squares regression line is -0.868.

• The equation of the least squares regression line is y=-0.868-1.6914x.

Tags

CCSS.HSS.ID.C.7

CCSS.HSS.ID.C.8

Above is the scatter plot (with the least squares regression line) for calories and protein (in grams) in one cup of 11 varieties of dried beans. The computer output for this regression is included. Which of the following best describes what the number s=3.37648 represents?

• The slope of the regression line is 3.37648.

• The standard deviation of the explanatory variable, calories, is 3.37648.

• The average error when using the LSRL to make predictions.

• The ratio of the standard deviation of protein to the standard deviation of calories is 3.37648.

Tags

CCSS.HSS.ID.B.6

CCSS.HSS.ID.C.7

The computer output is used to predict helicopter flight time from drop height.  Which is the correct equation for this relationship?

• (Time) = -0.03761+0.0057244(drop height)
• (time) = -0.03761+0.05838(drop height)
• (height)=-0.03761+0.0057244(time)
• (height)=0.0057244-0.03761(time)

Tags

CCSS.HSA.CED.A.2

CCSS.HSA.SSE.A.1

CCSS.HSF.BF.A.1

CCSS.HSF.LE.A.2

CCSS.HSS.ID.C.7

Given the image of linear regression computer output, what would the correlation coefficient be?

• .922
• .96
• -0.03761
• 28.37

Tags

CCSS.HSS.ID.C.8

The following computer output describes the relationship between y = height (in cm) and x = foot length (also in cm) for 12 randomly selected students from the British Census @ Schools database. The scatterplot for this relationship show a roughly linear shape. Which of the following is an equation of least-squares regression line for these data?

• Height = 117.99 + 1.878 (Foot Length)
• Foot Length = 117.99 + 1.878 (Height)
• Height = 1.878 + 117.99 (Foot Length)
• Foot Length = 1.878 + 117.99 (Height)

Tags

CCSS.HSA.CED.A.2

CCSS.HSS.ID.B.6

CCSS.HSS.ID.C.7

CCSS.HSS.ID.C.8

Data obtained from a group of high school seniors comparing age and the number of hours spent on the telephone. The resulting regression equation is

Predicted number of hours = 0.123(age)+2.57 with r =0.866

What percentage of the variation in the number of hours spent on the telephone can be explained by this least-squares regression model?

• 0.75%

• 75%

• 0.866%

• 86.6%

• This value cannot be found with the given information.

Tags

CCSS.HSS.ID.C.8

Above is a scatter plot (with the least squares regression line) for calories and protein (in grams) in one cup of 11 varieties of dried beans.  The computer output for this regression is below the plot. Which of the following best describes what the number S = 3.37648 represents?

• The slope of the regression line is 3.37648.
• The standard deviation of the explanatory variable, calories, is 3.37648.
• The standard deviation of the response variable, protein content, is 3.37648.
• The standard deviation of the residuals is 3.37648.

What does r² stand for?

• correlation coefficient
• coefficient of determination
• slope of the line of best fit (LOBF) for a sample
• slope of the line of best fit (LOBF) for a population

Tags

CCSS.HSS.ID.B.6

CCSS.HSS.ID.C.8

Twenty-five assembly-line workers participated in a study to investigate the relationship between experience and the amount of time required to complete an assembly task. Assembly time (in minutes) and number of months the worker had been employed on the assembly line were measured for each worker. The resulting data on time to complete assembly and number of months on the assembly line were used to produce the computer output in the picture.

Predict the time required to complete the assembly for an employee with 10 months of experience.

• 81.6 min

• 90.6 min

• 110.4 min

• 120.7 min

Tags

CCSS.HSA.CED.A.2

CCSS.HSS.ID.B.6

CCSS.HSS.ID.C.7